1. Technical Field
The present invention relates generally to network security protocols and, in particular, to a method of extending to an intermediary the privacy of a secure session between a client and a server.
2. Description of the Related Art
Network security protocols, such as Netscape's Secure Sockets Layer protocol (SSL) and the Internet Engineering Task Force (IETF) Transport Layer Security protocol (TLS), provide privacy and data integrity between communicating applications. These protocols, for example, are commonly used to secure electronic commerce transactions over the Internet.
Recently, the computer industry has sought to add computer processing and communications capabilities to devices other than what would normally be considered a traditional computer. Such devices are quite varied and include, for example, personal digital assistants (PDAs), business organizers (e.g., IBM® WorkPad® and the 3Com® PalmPilot®,), smartphones, cellular phones, other handheld devices, and the like. For convenience, these devices, as a class, are sometimes referred to as “pervasive computing” clients as they are devices that are designed to be connected to servers in a computer network and used for computing purposes regardless of their location.
Pervasive computing clients, however, typically do not support the full function set of an HTML Windows-based client. As a result, transcoding services typically are required to translate information to be rendered on the pervasive client from one source markup language (e.g., HTML) to another (e.g., HDML or handheld device markup language). The provision of transcoding services over a secure network connection, however, is problematic. In particular, there is a fundamental conflict between the security and transcoding services because traditional security protocols such as SSL and TLS are designed precisely to prevent a third party from intervening in the communication between the client and the server.
Restricting third party intervention in a secure session is also problematic in other applications. For example, if a client is located behind a firewall, SSL/TLS communications to servers in the outside network cannot be readily audited or otherwise monitored. Thus, data records or other sensitive information can be transmitted from the client, possibly without administrative authorization. As another example, a client that communicates with a server over a secure connection cannot take advantage of third party caching or pre-fetch mechanisms that would otherwise be useful in reducing network resource demands and enhancing communications between the devices.
It would be desirable to provide a mechanism by which a client could delegate enough security information to a proxy to enable the proxy to perform a given function (e.g., transcoding, auditing, monitoring, caching, pre-fetching, encryption/decryption on behalf of the client, etc.) without diluting the security of the network protocol.
The present invention solves this important problem.